From patchwork Tue Apr 20 09:43:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 12213661 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E76CFC433B4 for ; Tue, 20 Apr 2021 09:43:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E71C613AE for ; Tue, 20 Apr 2021 09:43:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230511AbhDTJoT (ORCPT ); Tue, 20 Apr 2021 05:44:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229937AbhDTJoS (ORCPT ); Tue, 20 Apr 2021 05:44:18 -0400 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECE00C06174A for ; Tue, 20 Apr 2021 02:43:47 -0700 (PDT) Received: by mail-pl1-x62b.google.com with SMTP id p16so15418934plf.12 for ; Tue, 20 Apr 2021 02:43:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=8zGycjEf+w5ATtSrKPNMDPKepC5i8j4NCy1WccYtrWo=; b=QqOpWHbt6U8N2elVbpSCNvzZXuOjgB9rFEjgBLcbbol//NpfpDX4uBQ7hJFYXHf/sR b9Bndqc5ia4cglVJSHXsuG1Pic44JZCtYzjoseI6ioscGu0bXioBJ+QP6KZC5xJrhscl o/YUdbHMWCrJKdbiQe/JGj3hzUoQ6HLC23goS0WQHE1hRD0ok6lwzbFXIkgBxY1ktLPk SPMsBpMCXtGhn8l0Agl7LhQiCCmdi/dMY+CWXkZ9Fnqs0OJdNgL1CgZ39QY/Qh6nKQ8a W3XmuzCJnIcWteB2f7/NMkO/MUZ1CnVkvRJvaQCVHtWdeoZjEnZybXm+ASgGtbCr8455 g8fQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=8zGycjEf+w5ATtSrKPNMDPKepC5i8j4NCy1WccYtrWo=; b=Zuw3ynSceAnqNvmuPzA7Wh5fG/b6euxOl0goStrbNsnCWG+kZSYDA0SR0FdN3ECk1z mNOy5c0bgDV0CB7CCGaqMGjoH8IedU/omps7Qs+89+g/ttM6spNskEZFezfivcABNPpa ZElxUMpXcr5lhuDjn2i7/iZJFslg6EEK5JHzVf0+7+wGyvr/jY00CNCVVME8aTTjUB0m tkjcezcneWeDbyjquFlpxZAvt1/eOT/d2THVLLIv8kLBvH0M9o+BQ3slbZ8Z6j9TOlXB 6Ti7oXy1CweAgFO6TMS64Rfw7FUOdDfCPty+/u2OjUNJs4eggLvGLUeMvHRlF2u2uT3+ Nv6Q== X-Gm-Message-State: AOAM530HNqCDC7fJa3+KdCOkngqifIEmi7kOd0gHhza5qL12vupeH1+h R8ZnZOFi/xr7+oX/9CYUIdQ= X-Google-Smtp-Source: ABdhPJwrpnp9YcLIIGqvPc+Gv1KTSyYxQkHFofF+TIndrIZ21eYxCcGBZ+x8KHLRLCC5ElfG0rLZLw== X-Received: by 2002:a17:90a:1b4b:: with SMTP id q69mr3961950pjq.188.1618911827553; Tue, 20 Apr 2021 02:43:47 -0700 (PDT) Received: from edumazet1.svl.corp.google.com ([2620:15c:2c4:201:71c5:2f2b:f562:605b]) by smtp.gmail.com with ESMTPSA id u1sm14783495pgg.11.2021.04.20.02.43.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Apr 2021 02:43:47 -0700 (PDT) From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski Cc: netdev , Eric Dumazet , Eric Dumazet , syzbot , Guenter Roeck , Mat Martineau , Xuan Zhuo , Jason Wang , "Michael S. Tsirkin" , virtualization@lists.linux-foundation.org Subject: [PATCH net-next] virtio-net: fix use-after-free in page_to_skb() Date: Tue, 20 Apr 2021 02:43:41 -0700 Message-Id: <20210420094341.3259328-1-eric.dumazet@gmail.com> X-Mailer: git-send-email 2.31.1.368.gbe11c130af-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Eric Dumazet KASAN/syzbot had 4 reports, one of them being: BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:191 [inline] BUG: KASAN: slab-out-of-bounds in page_to_skb+0x5cf/0xb70 drivers/net/virtio_net.c:480 Read of size 12 at addr ffff888014a5f800 by task systemd-udevd/8445 CPU: 0 PID: 8445 Comm: systemd-udevd Not tainted 5.12.0-rc8-next-20210419-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436 check_region_inline mm/kasan/generic.c:180 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186 memcpy+0x20/0x60 mm/kasan/shadow.c:65 memcpy include/linux/fortify-string.h:191 [inline] page_to_skb+0x5cf/0xb70 drivers/net/virtio_net.c:480 receive_mergeable drivers/net/virtio_net.c:1009 [inline] receive_buf+0x2bc0/0x6250 drivers/net/virtio_net.c:1119 virtnet_receive drivers/net/virtio_net.c:1411 [inline] virtnet_poll+0x568/0x10b0 drivers/net/virtio_net.c:1516 __napi_poll+0xaf/0x440 net/core/dev.c:6962 napi_poll net/core/dev.c:7029 [inline] net_rx_action+0x801/0xb40 net/core/dev.c:7116 __do_softirq+0x29b/0x9fe kernel/softirq.c:559 invoke_softirq kernel/softirq.c:433 [inline] __irq_exit_rcu+0x136/0x200 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 common_interrupt+0xa4/0xd0 arch/x86/kernel/irq.c:240 Fixes: fb32856b16ad ("virtio-net: page_to_skb() use build_skb when there's sufficient tailroom") Signed-off-by: Eric Dumazet Reported-by: syzbot Reported-by: Guenter Roeck Reported-by: Mat Martineau Cc: Xuan Zhuo Cc: Jason Wang Cc: "Michael S. Tsirkin" Cc: virtualization@lists.linux-foundation.org Acked-by: Michael S. Tsirkin Acked-by: Jason Wang --- drivers/net/virtio_net.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 8cd76037c72481200ea3e8429e9fdfec005dad85..2e28c04aa6351d2b4016f7d277ce104c4970069d 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -385,6 +385,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, struct sk_buff *skb; struct virtio_net_hdr_mrg_rxbuf *hdr; unsigned int copy, hdr_len, hdr_padded_len; + struct page *page_to_free = NULL; int tailroom, shinfo_size; char *p, *hdr_p; @@ -445,7 +446,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, if (len) skb_add_rx_frag(skb, 0, page, offset, len, truesize); else - put_page(page); + page_to_free = page; goto ok; } @@ -479,6 +480,8 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, hdr = skb_vnet_hdr(skb); memcpy(hdr, hdr_p, hdr_len); } + if (page_to_free) + put_page(page_to_free); if (metasize) { __skb_pull(skb, metasize);